Cartridge Filter

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,448
SW Indiana
#2
Cartridge filters already filter very small particles. Anything that would be added to the filter would clog it. If you have a problem, you might try adding a clarifier to the pool, or inspecting the cartridges for tears.

A common reason for poor filter performance is lack of flow through the filter due to clogged media (cartridges in your case). The filter is filtering the small stuff out, but only a small portion of the pool is being filtered. This is accompanied by high pressure readings.
 
#3
I use a small quantity of DE (diatomaceous earth) with my cartridge filter. This is specifically mentioned in my Pentair Clean and Clear Cartridge manual:

"Note: When the cartridge element filter is used on new pools and after cleaning the elements, introduce into the system .5 pound of diatomaceous earth per every 100 squre feet of filter area, (a one-pound coffee can equals .5 pounds of diatomaceous earth). Mix the diatomite with water and pour it into the skimmer after the pump is primed and the system is operating. This will enhance the filtration of your water."

I like doing this for a couple reasons:
1) I had a pool with a DE filter for 25 years and was very please with the job the DE did. Generally DE filters down to a smaller particle size than a cartridge filter.
2) If my cartridge filter starts failing, I'll be able to observe DE leaking through the filter and into the pool. This will give me a good indication that it is time to replace the cartridge filter.

Mike
 
#5
Rangeball:

I would guess it's probably not as effective as a regular DE filter. The .5 pound per 100 square feet provides only a real thin coat of DE on the Cartridge Filter.

In my case the water is crystal clear. My pool is inside a pool cage so there is very little debris entering the pool. I only run my pool pump 3 hours a day year round.

Mike
 
G
#6
mikemctx said:
I use a small quantity of DE (diatomaceous earth) with my cartridge filter. This is specifically mentioned in my Pentair Clean and Clear Cartridge manual:

"Note: When the cartridge element filter is used on new pools and after cleaning the elements, introduce into the system .5 pound of diatomaceous earth per every 100 squre feet of filter area, (a one-pound coffee can equals .5 pounds of diatomaceous earth). Mix the diatomite with water and pour it into the skimmer after the pump is primed and the system is operating. This will enhance the filtration of your water."

I like doing this for a couple reasons:
1) I had a pool with a DE filter for 25 years and was very please with the job the DE did. Generally DE filters down to a smaller particle size than a cartridge filter.
2) If my cartridge filter starts failing, I'll be able to observe DE leaking through the filter and into the pool. This will give me a good indication that it is time to replace the cartridge filter.

Mike
What the DE does is 'dirty' the filter. A dirty filter will filter better than a clean filter. However, the continued use of DE will clog the filter material and require changing the cart much sooner than without continued use of DE. The DE is fine for a NEW cartridge or, as the instructions say, on a new pool (plaster) with a lot of plaster dust that needs to be filtered out but for normal operation it should not be necessary, you are not going to gain that much and it will shorten your 'run time' (time between cleanings) considerably if you add DE each time. A much safer alternative to DE for cartridge filters is a cellulose based DE substitute filter aid.
(I have a Clean and Clear 150 myself, btw.)
 
#7
Waterbear:

Thanks for the info. I hadn't noticed any decrease in run time yet - perhaps that will occur as more time passes. So far the filter is only 2 1/2 years old and I've been using DE for 9 months. I normally clean the filter every 2 months, even though the pressure never shows an increase.

I have noticed that it's easier to clean the filter when I use DE. The dirt and little bugs are on top of the DE layer, so as I rinse off the DE - all the nasty stuff rinses away with it. Before using DE it was more difficult trying to get the dirt and bugs out of the folds of the filter.

Mike
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#8
Keep in mind that cartridge filters vary somewhat. Some handle the addition of DE far better than others. In some filters the DE gets embedded in the filter fabric and essentially clogs the filter permanently. Other filters allow the DE to be washed off.